1964 Dart V-8 Auto Tranny Fluid??

Dexron III is easy to find everywhere and cheap. No service manual anywhere on the face of the planet recommends Dex/Merc in a Torqueflite. It probably wouldn't hurt it, but why take a chance? We don't even list Dexron II in our electronic or printed catalogs, so it will probably be difficult to find. Since Dexron III supersedes anything before it and is readily available, run it. You "could" run Dexron VI, but it's more expensive and not necessary. So as long as III is available, that's what I would use.